Rivet



Aug. 9, 1927. 1,638,165

H. V. RAU

RIVET Filed July 16. 1924 Patented Aug. 9, 1927.

UNITED STATES PATENT OFFICE.

HENRY V. BAU, OF BBOOHYN, NEW YORK, ASSIGNOR T EDWARD B; BTIHTSON COKPANY, 0F BROOKLYN, NEW YORK.

BIV'ET.

Application Illed July 16,

The invention relates to improvements in rivets of the bifurcated type. Qne of .the objects of the invention 'is to provide a rivet of this kind which will have excellent penetrative qualities, and which, when clinched,

will securely hold itself in position with respect t0 the material through which it has been driven. To that end I have designed a bifurcated rivet with legs of progressively l" increasing cross-sectional area from the ends of the legs towards the head, and with surface interruptions on the outer faces of the legs. Preferably the shank of the rivet is initially a cylinder, circular in cross-section,

l5 and the prongs are formed by cutting a s lot in the shank, of progressively decreasing Width from the outer end of the cylinder to wards the rivet head. The surface interruptions on the outer faces of the prongs 3" may be formed either before or after the SlOttIig, and may be of various kinds, as hereinafter set forth.

In a further developed form of the invention the prongs are externally threaded, so that the rivet may function as such, or may, if desired, be used as a screw in connection with a tapped socket or the 1ike, with advantages due to structure and methods of manufacture which Wil] be explainedhereinafter.

Other objects and aims of the invention, more or less broad than those stated above, together With the advantages inherent, will be in part obvious and in part specitically referred to in the course of the following description of the elements, combinations, arrangements of parts, and applications of principles constituting the invention; and the scope of protection contemplated will appear from the claims.

In the accompanying drawings, which are to be taken as part of this specification, and in which I have shown merely a preferred form of embodiment of the invention.

Figure l is an elevation of a pronged rivet embodying my invention;

Figure 2 is a similar view of the same, as turned on its axis through an arc of 90;

Figure 3 is an end view of the saine, look4 ing at the ends of the prongs; and

IFigures 4 and 5 are views, similar to Figures 1 and 2, respectively` illustrating a inodied forni of the device.

Referring to the numerals on the drawings, the head of a rivet is indicated at 6,

1924. Serial N0. 728,253.

and it may be of any usual or preferred t ype. The shank that extends awav from the head is preferably initially a cv'linder, circular in cross-section, and the shank iS divided into prongs 7, 8, by cutting a diainetrical slot from the outer end of the cylinder towards the head, widest at the outer end, and of progressively decreasing width towards the head. The effect of this operation is to form prongs that are of pro ressively increasing cross-sectional area from ther outer ends towards the rvet-head, and with the outer faces of the prongs defined by longitudinal lines substantially parallel to the axis of the rivet, except as the legs may he slightly spread apart in the slotting operation. Either before or after the slottiug operation I form surface interruptions externally of the prongs. For manufacturing reasons I prefer that this operation shall he performed on the solid shank, before the slotting. The surface interruptions may be merely parallel transverse grooves 10, as indicated in Figures 4 and 5, or sections of a thread ll, as in Figures 1 and 2.

A rivet fashioned as above will readily penetrate materials with which it is designed to be used, without buckling, because of the small cross-section of the prongs at their outer ends, and the progressive increase in cross-section towards the head. VAnd because the inner faces of the prongs'onverge towards the head, there is no tendency for the prongs to close towards each other as the rivet is driven. When, however, the rivet is clinched, the outer faces of the prongs, because of their surface interruptions, make a firm frictional hold, or interlock, with the material into which the rivet has been driven. VVhei'e the surface interruptions have been formed by a thread 11, the shank can be entered into a tapped socket or the like the rivet functioning as a screw. To that end the head 6 may be kerfed, as indicated at 12, like the head of a screw. When the article is used as a screw I find that it is advisable, before entering it into the screw-hole-` to spread the prongs apart slightly; this is not always necessary, because ordinarily the prongs are left in a slightly spread condition by the slotting operation. In many situations it is found that the device serves very Well, holding itself in position against backing out due to vibration, etc. This is because of the slight spread of the prongs and the tendency of tie prong ends to resume the spread condition from which they have been forced by the compression to which they have been subjected iii entering them into, and in which they are held by the walls of the screw-hole. llurtherinore, the fact that the shank is bifurcated, and not solid, helps to kee it in place, because in case of any sligit movement due to vibration or the like, some part of one or nioreof the four prong edges will come into arresting contact with the screw-hole Wall. In cases where the tapped hole runs all the way through a thickness of materialfor instance, and the ends of the prongs extend beyond the face of the material, the prongs may be decidedly lient, even to the extent of forcing their outer faces against the material, and so hold the rivet-screw positively against rotation und Withdrawal.

I claim:

1. A rivet having a bifurcated shank, the prongs of which are of progressively increasing cross-section in the directionl away from their ends and separated by a diametrical slot of decreasing width in the direction away from the prong ends, the external surface of said rivet substantially maintaining its` original cylindrical shape and the prongs having external surface interruptions.

2. A rivet havino' a bifurcated shank, the prongs of whiiii are of progressively increasing cross-section in the direi-tion away from their ends and separated hy a diametrical slot of dei-reusing width in the direction away from the prong ends, the external surface of said rivet substantially maintaining its ori inul cylindrical shape, and the prongs having external surface interruptions in the forni ol' a mutilated thread.

3. A rivet having a hit'unrated shank, the

prongs of which are of progressively iucreas ing cross-section in the direction uwav from their ends and separated by a. dianietrical slot of decreasing width in the direction uaway from the prong ends, the external surface of said rivet substantially maintaining its original cylindrical shape, the prongs having external surface interruptions in the form of a mutilated thread, the rivet having a kerfed head. v

In testimony whereof I atx my signature.

HENRY V. RAU.

s read of the prongs and the tendency of tie prong ends to resume the spread condition from which they have been forced by thil comircssion to which they have been subjected in entering them into, and in which they are held by the walls of the screw-hole. Furthermore, the fact that the shank is bifnrcated, and not solid, helps to kee it in place, because in case of any sligit movement due to vibration or the like, some part of one or more of the four prong edges will come into arresting contact with the screw-hole wall. In cases where the tapped hole runs all the way through a thickness of material, for instance, and the ends of the prongs extend beyond the face ot the material, theprongs may he decidedly lient, even to the extent of forcing their outer faces against the material, and so hold the rivet-screw positively against rotation and withdrawal.

I claim:

1. A rivet having a hifurcated shank, the prongs of which are of progressively increasing cross-section in the direction away troni their ends and separated by a' diametriral slot of decreasing width in the direction away from the prong ends, the external A rivet having a hifurrated shank, the

prongs of which are of progressively increasing cross-section in thil direction away from their ends and separated hy a. diametrical slot of decreasing width in the direction away from the prong ends, the external surface of said rivet substantially its original cylindrical shape, the prongs having external surface interruptions in the form of a mutilated thread, the rivet having a kerfed head. i

In testimony whereof I affix my signature.

HENRY V. RAU.

CERTIFICATE or CORRECTION.

Patent No. l, 638, 165.

Granted August 9, 1927, to

HENRY V. RAU.

It is hereby certified that. the patent was erroneously written whereas said name son Company", as shown by name of the assignee in the above numbered and printed should have been written "Edward B. Stimpson Company," and printed u "Edwin B. Stimpthe records of assignments in this office; and

that the uid Letters Patent should be read with this correction therein that the me may Signed Seal.

conform to the record of the case in the Patent Office. and scaled this 4th day of October, A. D. 1927.

M. J. Moore, Acting Commissioner of Patents.

maintaining 50 CERTIFICATE 0F CORRECTlON.

Patent No. 1,638,165. Granted August 9, 1927, to

HENRY V. RAU.

lt is hereby certified that the name of the assignee in the shove numbered pstent wss erroneously written and printed "Edward B. Stimpson Compsny," whereas said name should have been written and printed as "Edwin B. Stimpson Company", ss shown by the records of assignments in this office; and thnt the said Letters Pstent should be read with this correction therein that the same may conform to the' record of the case in the Patent Office.

Signed and sesled this 4th dsy of October. A. D. 1927.

M. J. Moore. Sell. Acting Commissioner of Patents. 

